Nylon-based resins include engineering resins widely used as materials for interior and exterior components of automobiles. However, nylon-based resins can absorb moisture and thus can lack dimensional stability and can warp. An inorganic modifier such as glass fiber can be added to nylon resins to overcome these problems. Fiber reinforced nylon resins can be widely used for applications requiring excellent mechanical strength and heat resistance, such as structural materials, automobile interior and exterior materials, and the like.
However, adding an inorganic modifier can deteriorate impact resistance. Accordingly, there have been recent attempts to improve the high moisture absorption properties of conventional nylon by adding a modified nylon having a benzene ring in the main chain, and to improve the impact strength of a mixture of nylon and an inorganic modifier by further adding an impact modifier. Nevertheless, adding the modified nylon may not sufficiently improve moisture absorptiveness and further can cause dimensional instability and warpage. In addition, adding the modified nylon may not overcome the problems of decreased mechanical strength even when an impact modifier is added.
In addition, when nylon resin is reinforced with an inorganic modifier such as glass fiber, a large amount of inorganic impact modifier is typically used to provide high whiteness due to the intrinsic color of resin. Accordingly, the glass fiber is shortened or the surface of the glass fiber is scratched due to friction between the inorganic impact modifier and the glass fiber reinforcing material, so the impact resistance and impact strength are decreased. Due to the intrinsic characteristics of the resin, this can also generate a phenomenon in which the surface of the resin becomes rougher after dipping in boiling water, which can reduce its usefulness in applications requiring a glossy surface.